Fuel cell with fuel passage layer having a wiring pattern

ABSTRACT

A fuel cell is provided. The fuel cell includes a power generator incorporated in a housing having air intake ports, an electrical terminal connected to a printed-wiring board, and connectors and a fuel passage for supplying fuel. The terminals are formed in such configurations as to be insertion-mounted on the printed-wiring board or to be surface mounted on the printed-wiring board. The fuel cell is directly mounted on the printed-wiring board. Thus, a cell housing part or a fixing mechanism, a connector, for example, do not need to be provided on an electric device on which the fuel cell is mounted and the structure of the device itself is simplified and miniaturized.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application claims priority to Japanese Patent Document Nos.P2001-294019 filed on Sep. 26, 2001; P2001-339444 filed on Nov. 5, 2001;P2002-002847 filed on Jan. 9, 2002; and P2002-262320 filed on Sep. 9,2002 the disclosures of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention generally relates to a fuel cell. Morespecifically, the present invention relates to a fuel cell forgenerating an electromotive force in a power generator by supplyinghydrogen and oxygen (air) as fuel gases and an electric device using thefuel cell.

A fuel cell that is a device for generating an electromotive force in apower generator by supplying hydrogen and oxygen (air) as fuel gases hasbeen hitherto proposed. The fuel cell of this type ordinarily has astructure that an electrolyte film (proton conductive film) issandwiched in between gas electrodes to obtain a desired electromotiveforce. Such a fuel cell has been expectedly applied to an electricvehicle or a hybrid type vehicle and progressively developed to be putto practical use. The fuel cell has been employed for the vehicle suchas a motor vehicle. In addition thereto, the fuel cell has been studiedto apply to new uses completely different from the uses of vehicles suchas motor vehicles by making use of an advantage that its lightweight andcompact form can be easily realized. For instance, a fuel cell which canbe used as a new power source in place of a dry cell or a rechargeablebattery which has been used as a power source of a portable electricdevice has been studied.

A compact fuel cell capable of being incorporated in various kinds ofelectric devices has been progressively studied in various ways and sometypes of fuel cells have been already proposed. Any of them has abattery itself made compact, however, it is not necessarily satisfactoryfrom an aspect that the fuel cell is incorporated in the electricdevice. For instance, when the previously proposed fuel cell isincorporated in the electric device, a cell housing part is provided inthe device side like ordinary dry cells, various kinds of secondarybatteries such as lithium-ion secondary batteries, and the like. Thus, amechanism for fixing the cell or a connector for wiring or the like isprovided therein.

Since the fuel cell needs fuel gas, fuel piping needs to be provided tosupply fuel. Since the piping is necessary, a mechanism for preventingthe leakage of fuel from the piping needs to be added.

When each of the fuel cells which have been conventionally proposed isapplied to the electric device, particularly to a compact portableelectric device, not only the entire part of the device is hardly madecompact, but also the design of the device is subjected to arestriction. Furthermore, manufacturing steps upon manufacturing thedevice are complicated.

When the fuel cell is incorporated in the electric device, someone mayutilize a structure that the power generator of the fuel cell isincorporated in a device main body and a fuel storage part, forinstance, a hydrogen tank is separately mounted on the device main body.In this case, the power generator needs to be arranged near the hydrogentank and the device undergoes a great restriction in its design. Whenthe power generator is separated from the fuel storage part, pipingserving as a fuel passage needs to be provided between them.Consequently, piping parts such as tubes needs to be drawn around in thedevice. Thus, the number of parts is increased and the form of thedevice itself is enlarged, so that an assembly work is complicated.

SUMMARY OF THE INVENTION

The present invention provides a new and improved fuel cell as comparedto conventional fuel cells, such as those described above, and anelectric device using this fuel cell. For example, the present inventionprovides a fuel cell without preventing an electric device using thefuel cell as a power source from being miniaturized and giving arestriction to the design of the electric device.

Further, the present invention can provide a fuel cell withoutincreasing manufacturing steps when an electric device is manufactured.The present invention can provide an electric device which can lighten arestriction in design while a fuel cell is incorporated in the electricdevice, can reduce the number of parts and miniaturize them and canrealize the simplification of manufacturing steps. The present inventioncan provide a new printed-wiring board functioning not only as a circuitboard, but also as a fuel passage and a method for manufacturing theprinted-wiring board.

Still further, the present invention can provide a connector for a fuelcell that can be used as a connector for an electric connection as wellas for a fuel joint between a power generating cell and a fuel supplysource.

Still further, the present invention can provide such a method formounting a fuel cell in which the leakage of fuel can be prevented andthe fuel cell can be mounted on an electronic circuit board such as aprinted-wiring board by using a conventional device mounted on theelectric device.

A fuel cell according to an embodiment of the present invention has apower generator incorporated in a housing having air intake ports, anelectrical terminal connected to a board, and connectors and a passagefor supplying fuel.

In an electric device according to an embodiment of the presentinvention, the fuel cell is directly mounted on the board. Since thefuel cell is directly mounted on the substrate, the electric deviceaccording to an embodiment of the present invention does not need toprovide a cell housing part, a mechanism for fixing the fuel cell, aconnector, or the like. on the device on which the fuel cell is mounted.Thus, the structure of the device itself is simplified and miniaturized.In the electric device having the board on which the fuel cell isdirectly mounted, restrictions in design such as the arrangements ofvarious kinds of devices or wiring patterns are decreased and wastefulwiring and spaces and the loss of output or the like are also reduced.

On an electronic board according to an embodiment of the presentinvention, the wiring patterns are formed and the fuel passages areformed. The electronic board according to an embodiment of the presentinvention having the above-described structure not only has a functionas an ordinary circuit board, but also has a function as fuel passages.Since the fuel passages are incorporated in a wiring board, theelectronic board can be treated like an ordinary electronic board. Sucha structure is a new structure characteristic of the present inventionand provides new uses for the electronic board.

In a method for manufacturing the electronic board according to anembodiment of the present invention, a fuel passage form layer on whichthe fuel passages are formed as an inner layer and a wiring layer onwhich wiring patterns are formed are laminated. Such a method is used sothat the electronic board also having a function as fuel passages can bemanufactured without substantially changing manufacturing processes of aconventional electronic board.

The electric device according to an embodiment of the present inventionincludes a power generator of the fuel cell and a fuel storage part forsupplying fuel to the power generator which are incorporated in anelectric device main body device, and a board. On the board, fuelpassages as well as wiring patterns are formed. The fuel is supplied tothe power generator from the fuel storage part through the fuel passageson the board. The electric device according to an embodiment of thepresent invention does not depend on the arranged position of the powergenerator or the fuel storage part and a restriction in design of thedevice is lightened. Since the fuel is supplied through the board,piping part such as tubes do not need to be pulled around. Thus, thenumber of parts is reduced and the device is miniaturized.

A connector for a fuel cell according to an embodiment of the presentinvention includes a printed-wiring board on which wiring patterns areformed and fuel passages are formed. An electric signal and fuel aresupplied and received through the printed-wiring board. The connectorfor the fuel cell of the present invention is used, for instance, as aconnector between a power generator of the fuel cell and a fuel supplysource, and exhibits a function as a connector for an electricconnection and a function as a fuel joint.

Another fuel cell according to an embodiment of the present inventionincludes a power generator incorporated in a housing having air intakeports, an electrical terminal connected to a wiring member, and aconnector for supplying fuel on a surface opposed to the wiring member.The wiring member used in the fuel cell according to an embodiment ofthe present invention has fuel passages formed in an inner layer andfuel supply ports as openings on the surface of an upper layer. In theelectric device according to an embodiment of the present invention, apart between the wiring member and the fuel cell is sealed with a resin.An adhesive or a moldable resin allows the fuel cell according to anembodiment of the present invention to be mounted on the electric deviceby fixing a part between the fuel cell and the wiring member.

The fuel cell according to an embodiment of the present inventionincludes a passage for supplying fuel to the fuel cell formed on awiring member. Accordingly, a cell housing part, a mechanism for fixingthe fuel cell, a connector, fuel piping, or the like do not need to beprovided on the device on which the fuel cell is mounted. As a result,the structure of the device is simplified and miniaturized. Since thefuel piping is not exposed, the fuel can be effectively sealed. Thus, astructure for preventing the leakage of fuel does not need to be added.According to an embodiment of the present invention, since the fuel cellis directly mounted on a printed-wiring board, restrictions in designconcerning the arrangements of various kinds of devices or wiringpatterns are decreased and wasteful wiring, piping or spaces, the lossof output, etc. are also decreased. The fuel cell is fixed to theprinted-wiring board with an adhesive or a mold resin, so that a devicesimilar to a method for mounting a conventional electric device cansimply fix the fuel cell and seal fuel.

Additional features and advantages of the present invention aredescribed in, and will be apparent from, the following DetailedDescription of the Invention and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic perspective view showing one example of a fuelcell according to an embodiment of the present invention which has ainsertion-mount type package structure.

FIG. 2 is a schematic sectional view showing one structural example of apower generator according to an embodiment of the present invention.

FIG. 3 is a schematic sectional view showing a disassembled state of thefuel cell shown in FIG. 1 according to an embodiment of the presentinvention.

FIG. 4 is a schematic sectional view showing an assembled stateaccording to an embodiment of the present invention.

FIG. 5 is a schematic perspective view showing one example of a fuelcell having a surface-mount type package structure according to anembodiment of the present invention.

FIG. 6 is a schematic sectional view showing a disassembled state of thefuel cell shown in FIG. 5 according to an embodiment of the presentinvention.

FIG. 7 is a schematic sectional view showing an assembled stateaccording to an embodiment of the present invention.

FIG. 8 is a schematic sectional view showing one example of a fuel cellin which plurality of power generators are incorporated according to anembodiment of the present invention.

FIG. 9 is an exploded perspective view showing one example of aprinted-wiring board according to an embodiment of the presentinvention.

FIGS. 10A, 10B and 10C are schematic sectional views showing one exampleof manufacturing processes of the printed-wiring board according to anembodiment of the present invention.

FIGS. 11A to 11E are schematic sectional views showing another exampleof manufacturing processes of a printed-wiring board according to anembodiment of the present invention.

FIGS. 12A to 12F are schematic sectional views showing a still anotherexample of manufacturing processes of a printed-wiring board accordingto an embodiment of the present invention.

FIG. 13 is a block diagram showing a schematic structure of an electricdevice having the printed-wiring board incorporated according to anembodiment of the present invention.

FIG. 14 is a block diagram showing one example of a using form of aconnector for a fuel cell according to an embodiment of the presentinvention.

FIG. 15 is a schematic perspective view of main parts showing an exampleof a configuration of the connector for the fuel cell according to anembodiment of the present invention.

FIG. 16 is a schematic perspective view showing the entire structure ofthe fuel cell according to an embodiment of the present invention.

FIG. 17A is a schematic plan view showing one example of a fuel cellhaving an insertion-mount type package structure, FIG. 17B is a sideview of the above and FIG. 17C is a partly sectional view of the aboveaccording to an embodiment of the present invention.

FIG. 18 is a schematic sectional view showing one structural example ofa power generator according to an embodiment of the present invention.

FIG. 19 is a schematic sectional view showing a disassembled state ofthe fuel cell shown in FIG. 17 according to an embodiment of the presentinvention.

FIG. 20 is a schematic sectional view showing an assembled state of thefuel cell shown in FIG. 17 according to an embodiment of the presentinvention.

FIGS. 21A to 21C respectively show each layer of the structure of theprinted-wiring board according to an embodiment of the presentinvention. FIG. 21A is a plan view of an upper layer, FIG. 21B is a planview of an intermediate layer and FIG. 21C is a plan view of a lowerlayer according to an embodiment of the present invention.

FIG. 22 is a perspective view showing a combination of theprinted-wiring board according to an embodiment of the presentinvention.

FIGS. 23A to 23C show steps for mount the insertion-mount type fuel cellon the printed-wiring board according to an embodiment of the presentinvention.

FIGS. 24A to 24C show steps of another embodiment for mount a fuel cellon a printed-wiring board according to an embodiment of the presentinvention.

FIG. 25 shows a state that the insertion-mount type fuel cell is mountedon the printed-wiring board to seal with a resin for enhancing anair-tightness according to an embodiment of the present invention.

FIG. 26A is a plan view showing one example of a fuel cell having asurface-mount type package structure according to an embodiment of thepresent invention. FIG. 26B is a side view thereof, and FIG. 26C is apartly sectional view thereof according to an embodiment of the presentinvention.

FIG. 27 is a schematic sectional view showing a state that the fuel cellshown in FIGS. 26A to 26C is disassembled according to an embodiment ofthe present invention.

FIG. 28 is a schematic sectional view showing a state that the fuel cellshown in FIGS. 26A to 26C is assembled according to an embodiment of thepresent invention.

FIGS. 29A to 29D show steps for mount the surface-mount type fuel cellon the printed-wiring board according to an embodiment of the presentinvention.

FIG. 30 shows an electric device having a printed-wiring board on whicha fuel cell and electronic parts are mounted according to an embodimentof the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention generally relates to fuel cells. In particular,the present invention relates to a fuel cell capable of generating anelectromotive force in a power generator by supplying hydrogen andoxygen (air) as fuel gases and an electric device using the fuel cell.

FIG. 1 shows one example of a fuel cell according to an embodiment ofthe present invention. The fuel cell shown in FIG. 1 uses ainsertion-mount type package called a dual inline package (DIP). One ortwo or more power generators 2 are incorporated in a housing 1. Air issupplied to a cathode side from air intake ports 3 provided on thehousing 1. Fuel (hydrogen) is supplied to an anode side from a fueljoint 4 likewise attached to the housing 1 to generate power.

A plurality of terminal pins 5 a and 5 b connected to anodes (fuelelectrodes) or cathodes (air electrodes) of the power generators 2 aredrawn out from the housing 1. An electric connection to an electricdevice is carried out through the terminal pins 5 a and 5 b. That is,the fuel cell having a structure shown in FIG. 1 is mounted on aprinted-wiring board by, for instance, inserting the terminal pins 5 aand 5 b into connecting holes provided on the printed-wiring boardincorporated in the electric device side and soldering them. Thus, theelectrodes of the fuel cell are electrically connected to wiring formedon the printed-wiring board so that electric power is supplied to thecircuit of the electric device side.

The power generator 2 has a structure that an ion conductive film 2 a isheld at both sides between an anode 2 b and cathode 2 c respectively asone electrode and peripheries thereof are sealed with seals 2 d, asshown in FIG. 2. This seal 2 d is provided for the purpose of preventinghydrogen from leaking to the cathode side 2 c. The seal 2 d may beformed by bonding together materials which are previously formed by aninjection molding or punching, or the like or may be directly formed onthe ion conductive film 2 a or the electrodes.

FIG. 3 shows a state that the fuel cell to which the present inventionis applied is disassembled. The fuel cell of this embodiment has astructure that the power generator 2 is sandwiched in between a pair ofcurrent collectors 6 and 7. The current collectors 6 and 7 respectivelyhave opening parts 6 a and 7 a provided for taking fuel. Hydrogen asfuel and oxygen (air) are taken into the anode 2 b and the cathode 2 cthrough these opening parts 6 a and 7 a.

The current collector 6 of the cathode 2 c side has a two-layerstructure. The structure includes an insulating material layer 6 b madeof an insulating material in an exposed side as the surface of thehousing 1 and a current collecting part 6 c made of a conductivematerial in a side coming into contact with the power generator 2. Thecurrent collector 7 of the anode 2 b side is made of a conductivematerial, and is not especially provided with such an insulatingmaterial layer as that provided in the current collector 6 of thecathode 2 c, side. Here, as the conductive material which forms thecurrent collecting part 6 c of the current collector 6 in the cathode 2c side or the current collector 7 of the anode 2 b side, a metallicplate, a carbon sheet or the like may be used. In addition thereto, whatis called a single-sided board that a conductive layer is formed on apolymer film, a glass epoxy board, a ceramic board, etc. may be used.Otherwise, a paste printing or plating may be applied to the powergenerator 2 to directly form a current collecting layer thereon.

The current collecting part 6 c of the current collector 6 or thecurrent collector 7 is electrically connected respectively to theterminal pins 5 a and 5 b through which an electric connection to theelectric device is achieved. The ends of the terminal pins 5 a and 5 bare desirably have forms, for instance, thin plate shapes or pin shapesso as to be inserted into the connecting holes provided in theprinted-wiring board. Further, the ends of the terminal pins 5 a and 5 bdesirably have such a rigidity as to be fixed to the printed-wiringboard. When the current collecting part 6 c of the current collector 6or the current collector 7 is made of the metallic plate, the ends ofthe terminal pins 5 a and 5 b are machined to the thin plate shapes orpin shapes, so that they may be provided integrally. The terminal pins 5a and 5 b may be separately provided and they may be mechanically andelectrically connected to the current collecting part 6 c of the currentcollector 6 or the current collector 7.

In the outside of the current collector 7 of the anode side, a hydrogensupply part 8 having a passage 8 a for hydrogen as fuel is arranged anda fuel joint 4 is fixed. Further, in the hydrogen supply part 8, openingparts 8 b are opposed to opening parts 7 a provided in the currentcollector 7. The hydrogen as the fuel is supplied to the anode 2 b ofthe power generator 2 through the passage 8 a, the opening parts 8 b andthe opening parts 7 a from the fuel joint 4. The hydrogen supply part 8may be formed as one part, or may be formed integrally with the currentcollector 7 or the housing 1.

The power generator 2, the current collectors 6 and 7 and the hydrogensupply part 8 as the above-described components are superposed togetherto have a laminated body. These components are fixed together with thehousing 1 to have a packaged body as shown in FIG. 4. In thisembodiment, the laminated body is packaged and the housing is formedsimultaneously by a resin mold. The housing 1 is formed integrally withthe laminated body. It is to be understood that a variety of structuresother than this structure may be employed. For instance, a structurethat the housing is divided into two upper and lower parts and thelaminated body is sandwiched in between these parts and fixed by screwsmay be used. In addition, a structure that the upper and lower housingparts are fixed by an ultrasonic welding or bonding process or the likemay be employed.

In the fuel cell having the above-described structure, when the hydrogenas fuel is allowed to enter the hydrogen supply part 8 so as to comeinto contact with the anode 2 b and air (oxygen) is allowed to enterfrom the opening parts 6 a so as to come into contact with the cathode 2c, a reaction represented by the following reaction formula is generatedin the anode 2 b side.H₂2H⁺+2e—

In the cathode 2 c side, a reaction represented by a reaction formuladescribed below is generated.½O₂+2H⁺+2e-H₂O+heat of reaction Q

In the entire part, a reaction represented by H₂+½O₂ H₂O is generated.That is, in the anode 2 b side, hydrogen discharges an electron tobecome a proton, passes through the ion conductive film 2 a to move tothe cathode 2 c side, and receives the supply of the electron in thecathode 2 c to react with oxygen. An electromotive force is obtained inaccordance with such an electrochemical reaction.

Now, another embodiment of a fuel cell according to the presentinvention will be described. The fuel cell of this embodiment uses asurface-mount type package form called a BGA (Ball Grid Array).

The basic structure of the fuel cell of this embodiment is the same asthat of the above-described embodiment. As shown in FIG. 5, a powergenerator 12 is contained in a housing 11. Air is supplied to a cathodeside from air intake ports 13 provided in the housing 11 and fuel(hydrogen) is supplied to an anode side from a fuel joint 14 likewiseattached to the housing 11 to generate electric power.

An electric connection to an electric device is carried out throughterminals 15. Here, the terminals 15 are formed in shapes of balls orprotrusions made of a conductive material such as solder differentlyfrom those of the above-described embodiment. The terminals 15 aremechanically and electrically connected to terminal parts formed on amount board of the electric device side.

FIG. 6 is a schematic sectional view showing a state that the fuel cellshown in FIG. 5 is disassembled. The structure of the contained powergenerator 12 is the same as that of the above-described embodiment. Anion conductive film 12 a has a structure that the conductive film isheld at both sides between electrodes, that is, an anode 12 b and acathode 12 c and peripheries thereof are sealed with a seal 12 d.

The power generator 12 is sandwiched in between a base substrate 17 anda hydrogen supply part 18. The base substrate 17 forms a part of thehousing 11 and employs, for instance, a resin substrate such as glassepoxy, phenolic resin, polyimide, and/or the like, or an inorganicsubstrate such as ceramics, glass, silicon, and/or the like. The basesubstrate 17 has a recessed part 17 a capable of housing the powergenerator 12. Air intake opening parts 17 b are formed on the bottompart of the recessed part 17 a. Cathode current collectors 19 are formedon the inner surface of the base substrate 17 as a surface that comesinto contact with the cathode 12 c of the power generator 12.

On the other hand, the hydrogen supply part 18 is arranged so as tocover the power generator 12 housed in the base substrate 17. Thehydrogen supply part 18 has a passage 18 a for hydrogen as fuel andhydrogen intake opening parts 18 b formed on a surface that comes intocontact with the anode 12 b of the power generator 12. On the surface ofthe hydrogen supply part 18 that comes into contact with the anode 12 bof the power generator 12, anode current collectors 20 are formedintegrally. Otherwise, the hydrogen supply part 18 itself may be made ofa conductive material to serve as an anode current collector.

The power generator 12 is sandwiched in between the base substrate 17and the hydrogen supply part 18 so that the current collectingstructures of the anode 12 b and the cathode 12 c of the power generator12 are realized. In this embodiment, the base substrate 17 has athree-layer structure. In the parts of the base substrate 17 that comeinto contact with the hydrogen supply part 18, wiring layers 21connected to the anode current collectors 20 are formed. Electricconnections between the respective layers are carried out through viaholes 22 and 23. The hydrogen supply part 18 is preferably fixed to thebase substrate 17 under this state. Further, the hydrogen supply part 18may be fixed to the base substrate 17 simultaneously with the attachmentof a cover substrate as described below. As a fixing method, a bondingmethod by a resin may be exemplified.

In the back surface side of the base substrate 17 located in the lowerpart of FIG. 6, a cover substrate 24 is provided. The power generator 12disposed in the recessed part 17 a of the recessed base substrate 17 andthe hydrogen supply part 18 are secured by the base substrate 17 and thecover substrate 24. In the cover substrate 24, via holes 25 and 26 areprovided so as to correspond to the via holes 22 and 23. Further, thevia holes 25 and 26 are provided with hemispherical terminals 15. As thehemispherical terminals 15, for instance, solder balls can be used. Thesolder balls are fixed to connecting terminals formed on aprinted-wiring board of an electric device side by performing areflowing process to achieve an electric connection.

FIG. 7 shows an assembled state of the fuel cell. Under the assembledstate, the housing 11 is formed and packaged by the base substrate 17and the cover substrate 24. The terminals 15 are arranged on the bottompart thereof. Accordingly, the fuel cell having the above-describedstructure is configured as a fuel cell having a surface-mount typepackage. The surface-mount type package form is not limited to the BGAand, for instance, a QFP (Quad Flat Package) or the like may be used.

Now, a structural example of a fuel cell in which a plurality of powergenerators, for instance, two power generators are incorporated will bedescribed below. FIG. 8 shows one example of a fuel cell with a BGApackage form in which the two power generators are incorporated. In thisexample, two sets of power generators 32 and 33 are disposed on both thesurfaces of a hydrogen supply part 34 in a housing 31. Further, on thehousing 31, air intake ports 35 are provided on both upper and lowersurfaces. The hydrogen supply part 34 has a fuel joint 36 to beconnected to an external fuel source likewise the above-describedembodiments.

Further, on both the surfaces of the hydrogen supply part 34, anodecurrent collectors 37 are formed. On the surfaces of the housing 31 thatcome into contact with the power generators 32 and 33, cathode currentcollectors 38 are formed, respectively. These current collectors areconnected to terminals 40 through via holes 39. The terminals 40 arerespectively formed in shapes of balls and can be mounted on the surfaceof a printed-wiring board of an electric device.

Now, a printed-wiring board or a method for manufacturing it to whichthe present invention is applied will be described. Further, an electricdevice and a connector for a fuel cell to which the printed-wiring boardand the method for manufacturing it are applied will be described indetail by referring to the drawings.

FIG. 9 shows one embodiment of a printed-wiring board according to thepresent invention. This printed-wiring board 101 has a structureincluding a first electric circuit wiring layer 102, a fuel passageforming layer 103 and a second electric circuit wiring layer 104. Thefuel passage form layer 103 is an inner layer. The fuel passage formlayer 103 is held from both sides between the first electric circuitwiring layer 102 and the second electric circuit wiring layer 104.

As a base material of the electric circuit wiring layers 102 and 104 orthe fuel passage form layer 103, arbitrary insulating materials such asa resin, a glass epoxy material, ceramics, glass, etc. may be used. Inthis case, a material having no or little leakage of fuel needs to beused.

On the fuel passage form layer 103, prescribed fuel passages 103 a areformed by grooving or boring. For instance, fuel is supplied to thepower generator of a fuel cell through these fuel passages 103 a. Thefuel passages 103 a formed by punching the fuel passage form layer 103to prescribed forms function as fuel piping by covering the upper andlower parts thereof with the electric circuit wiring layers 102 and 104.

The electric circuit wiring layers 102 and 104 respectively havestructures the same as that of a wiring layer used in an ordinarymulti-layer wiring board and form a single-sided board, a double-sidedboard, or a multi-layer board. Then, wiring patterns 102 a and 104 a areformed in accordance with electric circuits on both surfaces, a singlesurface, or each layer of the multi-layer board. The wiring patterns 102a and 104 a are formed, for instance, by patterning a copper foil by aphotolithography technique. The electric circuit wiring layers 102 and104 may be electrically connected together, or may be separated toindividually function. Especially, when the electric circuit wiringlayers 102 and 104 are electrically connected together, the fuel passageform layer 103 may be formed as a double-sided wiring board on whichwiring patterns are formed. The electric circuit wiring layers 102 and104 may be electrically connected together through this fuel passageform layer 103.

These electric circuit wiring layers 102 and 104 and the fuel passageform layer 103 are laminated and pressed to be integrated so that theprinted-wiring board 101 having the fuel passages incorporated isformed. This printed-wiring board 101 is similar to a conventionalprinted-wiring board except that the fuel passages 103 a areincorporated therein and can be incorporated in an electric device orthe like likewise the ordinary printed-wiring board. At this time, sincethe fuel passages 103 a are contained in the printed-wiring board 101,they do not interfere with a structure.

In this embodiment, although the fuel passage form layer 103 undergoes agrooving and a boring to form the fuel passages 103 a, the presentinvention is not limited thereto, and, for instance, pipe shaped partsmay be incorporated to form fuel passages. In this case, the pipe shapedparts may be embedded in a resin layer or an adhesive layer and anelectric circuit wiring layer may be bonded to both the sides or a oneside thereof. In the above-described embodiment, although the fuelpassage form layer is formed in one layer, the present invention is notlimited thereto, and the fuel passage form layers may be formed in aplurality of layers. In this case, multi-layer wiring boards in whichthe fuel passages are already contained may be laminated.

Now, a method for manufacturing a printed-wiring board according to anembodiment of the present invention will be described. To manufacturethe printed-wiring board according to an embodiment of the presentinvention, various methods may be considered. As a first example of themethods, a double-sided wiring board is punched to the forms of fuelpassages and wiring boards are laminated on the upper and lower sides ofthe double-sided board. FIG. 10 shows one embodiment of theabove-described manufacturing processes.

In this embodiment, firstly as shown in FIG. 10A, a double-sided wiringboard 111 serving as a fuel passage form layer is prepared to formpunched holes 112 as fuel passages by, what is called a router cuttingor a laser cutting. The punched holes 112 are formed so as to avoidwiring patterns 111 a and 111 b respectively provided on both thesurfaces of the double-sided wiring board 111. At least one end of thepunched hole 112 is formed to face the peripheral edge of thedouble-sided wiring board 111 to serve as a fuel inlet port or a fueloutlet port. Otherwise, the punched hole 112 may be formed so that itsend does not face the peripheral edge of the double-sided wiring board111. Then, a hole communicating with the punched hole 112 may be formedon any of the wiring boards laminated on the upper and lower sides ofthe double-sided wiring board 111 to serve as a fuel inlet port or afuel outlet port. The wiring patterns 111 a and 111 b provided on boththe surfaces of the double-sided wiring board 111 are electricallyconnected together through holes 111 c at required positions.

Now, as shown in FIG. 10 b, two wiring boards 113 and 114 are preparedand positioned respectively on the surfaces of the double-sided wiringboard 111 and superposed on the double-sided wiring board 111 on whichthe punched holes 112 are formed through adhesive layers 115 and 116.Wiring patterns 113 a and 113 b or wiring patterns 114 a and 114 b arealso formed on these wiring boards 113 and 114 likewise theabove-described double-sided wiring board 111. Respective layers areelectrically connected through holes 113 c.

Under this state, a laminated body is pressed. Thus, as shown in FIG.10C, the printed-wiring board in which the three wiring boards 111, 113and 114 are formed integrally is obtained. In this printed-wiring board,after the three wiring boards are laminated and integrated, a throughhole 117 passing through the three wiring boards 111, 113 and 114 isformed so that an electric connection is realized between these wiringboards 111, 113 and 114. Further, in the wiring board 114, fuel holes118 are formed at positions corresponding to the punched holes 112 toserve as fuel inlet ports or fuel outlet ports of the punched holes 112as the fuel passages. The manufactured printed-wiring board has the fuelpassages incorporated and is formed as a multi-layer wiring board sothat the electric connection and the supply of fuel can be achievedthrough the printed-wiring boards.

FIGS. 11A to 11E show another embodiment of manufacturing processes of aprinted-wiring board. In this embodiment, the use of photolithographytechnique allows fuel passages to be formed. That is, in thisembodiment, as firstly shown in FIG. 11A, a wiring board 121 isprepared. In the wiring board 121, wiring patterns 121 a and 121 b areformed on each layer of a double sided board or a multi-layer board andthese wiring patterns 121 a and 121 b are electrically connectedtogether through a through hole 121 c. A photosensitive resin is appliedon one surface of the wiring board 121 to form a photosensitive resinlayer 122.

Then, as shown in FIG. 11B, the photosensitive resin layer 122 ispatterned in accordance with necessary piping forms to form groove parts122 a serving as fuel passages. The use of ordinary photolithographytechnique may make it possible to pattern the photosensitive resin layer122. Specifically, the photosensitive resin layer 122 selectivelyexposed through a mask and the exposed photosensitive resin layer isdeveloped.

Now, as shown in FIG. 11C, a copper (Cu) foil 124 in which an adhesivelayer (resin layer) 123 is formed is superposed on and bonded to thephotosensitive resin layer 122. At this time, the thickness of theadhesive layer 123 may be set to arbitrary strength by consideringstrength. The thickness is preferably small as much as possible.Further, an adhesive having little fluidity is desirably used not tobury the fluid passages. The copper foil 124 having the adhesive layer123 is laminated so that the groove parts 122 a formed on thephotosensitive resin layer 122 are closed and the fuel passages areformed.

After the above lamination, as shown in FIG. 11D, the copper foil 124 isetched to form a prescribed wiring pattern. The ordinaryphotolithography technique may be also used to etch the copper foil 124.

Finally, as shown in FIG. 11E, a through hole 125 is formed toelectrically connect the wiring patterns 121 a and 121 b formed on thewiring board 121 to the wiring pattern formed by etching the copper foil124. Further, fuel holes 126 communicating with the groove parts 122 aformed on the photosensitive resin layer 122 are bored on the wiringboard 121 to serve as fuel inlet ports or fuel outlet ports.

FIGS. 12A to 12F show a still another embodiment of a method formanufacturing a printed-wiring board. This embodiment has basically thesame processes as those shown in FIGS. 10A to 10C, however, is differentfrom the processes shown in FIGS. 10A to 10C from the viewpoint that theprocesses of this embodiment more promote a multi-layer structure.

Firstly, as shown in FIG. 12A, a single-sided copper-clad board 131serving as a fuel passage form layer is prepared and punched holes 132as fuel passages are formed by what is called a router cutting. A copperfoil 131 b is bonded to a base material 131 a to form the single-sidedcopper-clad board 131 and the punched holes 132 pass through the basematerial 131 a and the copper foil 131 b.

Then, as shown in FIG. 12B, a double-sided wiring board 134 is bonded tothe single-sided copper-clad board 131 through an adhesive layer 133.The double-sided wiring board 134 has wiring layers formed on bothsurfaces. In this step, only one wiring layer on one surface in contactwith the adhesive layer 133 undergoes a patterning process to form awiring pattern 134 a and a copper foil 134 b on the other surface is notpatterned.

Subsequently, as shown in FIG. 12C, a through hole work is carried outto form through holes 135 passing through the single-sided copper-cladboard 131 and the double-sided wiring board 134. Further, a platingprocess is applied to form the plated through holes and a plated layer136. This plated layer 136 is formed on an entire surface including theinner parts of the punched holes 132 of the single-sided copper-cladboard 131. After the plated layer 136 is formed, as shown in FIG. 12D,the plated layer 136 and the copper foil 134 b on the outer part of thedouble-sided wiring board 134 are patterned in accordance with anelectric circuit to respectively form wiring patterns.

Further, single-sided copper-clad boards 137 and 138 are prepared andbonded to the single-sided copper-clad board 131 and the double-sidedwiring board 134 through adhesive layers 139 and 140 as shown in FIG.12E. Copper foils 137 b and 138 b are respectively bonded to basematerials 137 a and 138 a to form the single-sided copper-clad boards137 and 138. The single-sided copper-clad board 137 is superposed on andbonded to the single-sided copper-clad board 131 so that the punchedholes 132 are closed and the fuel passages are formed. Finally, thecopper coils 137 b and 138 b as outermost layers are etched to formprescribed wiring patterns and complete the printed-wiring board.

The printed-wiring board according to an embodiment of the presentinvention is mounted and used on various types of electric devices,especially in electric devices in which a fuel cell is incorporated.FIG. 13 shows one example of a form that the printed-wiring boardaccording to the present invention is incorporated in the electricdevice. In this example, a power generator 142 of a fuel cell and a fuelstorage tank 143 are incorporated in an electric device main body 141.Electric power is supplied to a driving circuit part contained in theelectric device main body 141 by the electromotive force of the powergenerator 142. Here, a printed-wiring board 144 in which fuel passagesare incorporated is mounted on the electric device main body 141. Fuel(hydrogen) used for a cell reaction in the power generator of the fuelcell is supplied to the power generator 142 from the fuel storage tank143 through the fuel passages of the printed-wiring board 144.

In the electric device in which the power generator 142 of the fuel cellis incorporated as described above, when the printed-wiring board 144 inwhich the fuel passages are incorporated is mounted and hydrogen as fuelis supplied to the power generator 142 from the fuel storage tank 143,the power generator 142 and the fuel storage tank 143 can be freelyarranged. Thus, a restriction in design can be lightened and the devicecan be miniaturized. Particularly, the printed-wiring board 144according to an embodiment of the present invention is mounted as acircuit board of the power generator 142 and used as the fuel passagesso that the structure can be simplified and the number of assembly stepscan be reduced. When a fuel connection between the power generator 142and the fuel storage tank 143 is carried out, piping parts such as tubesdo not need to be pulled around and the number of parts can be reduced.

The above-described printed-wiring board in which the fuel passages areincorporated can be used not only as the circuit board of the electricdevice, but also as a connector for a fuel cell. The concept of a usingform as a connector for a fuel cell is shown in FIG. 14. In thisembodiment, when fuel (hydrogen) needs to be supplied to a fuel cell161, the fuel cell 161 is connected to a fuel server (hydrogen server)163 through a connector 162 for a fuel cell having the printed-wiringboard incorporated to supply the fuel (hydrogen). The printed-wiringboard is interposed between the fuel server and the fuel cell so thatnot only the hydrogen as fuel can be supplied and received, but alsoinformation about, for instance, the delivery of the fuel can betransmitted by an electric signal.

As another embodiment of a connector for a fuel cell, the connector canbe used as a hydrogen delivery connector having hydrogen contained. Forexample, as shown in FIG. 15, the printed-wiring board is directly usedas a connector in a hydrogen delivery device 171 having such a form as amemory module employed in a personal computer or the like. In thisembodiment, electric contacts 172 of the incorporated printed-wiringboard are directly used as the electric contacts of the hydrogendelivery device 171. At the same time, fuel passages 173 incorporated inthe printed-wiring board face an outer part in this connector part andserve as joints for fuel piping. In this case, the delivery of theelectric signal and the hydrogen as fuel can be carried out at the sametime through the connector using the printed-wiring board.

Now, the fuel cell and the printed-wiring board according to anembodiment of the present invention and a method for connecting themwill be described in detail by referring to the drawings. FIG. 16schematically shows an embodiment of the present invention. In thisembodiment, a number of fuel cells 240 are mounted on a printed-wiringboard 210. A fuel supply tube 250 is connected to the printed-wiringboard 210 to supply fuel to the fuel cells 240 from the fuel supply tube250 through the printed-wiring board 210. Air is taken from air intakeports 204 a to supply electric current generated by the fuel cells 240to electronic parts disposed in parts except the printed-wiring board210 or drive an electric circuit formed on the printed-wiring board 210.

FIGS. 17A to 17C shows one embodiment of a fuel cell 241 according to anembodiment of the present invention. This embodiment uses asurface-mount type package called a small outline package (SOP). In thisembodiment, one or two or more power generators 203 are held andincorporated between an upper housing 201 and a board side housing 202.Air is supplied to a cathode side of the power generator 203 from airintake ports 204 b provided in the upper housing 201. Fuel such ashydrogen, methanol, or the like is supplied to an anode side of thepower generator 203 from fuel joints 205 as tubular fuel passagesattached to the surface (referred it to as a wiring member mountsurface, hereinafter) of the board side housing 202 which is opposed toa printed-wiring board 210 to generate power.

A plurality of terminal pins 206 a and 206 b connected to anodes (fuelelectrodes) or cathodes (air electrodes) of the power generators 203 aredrawn out from the upper housing 201 and the board side housing 202. Anelectric connection to the printed-wiring board 210 is carried outthrough the terminal pins 206 a and 206 b.

That is, the fuel cell 241 having a structure shown in FIGS. 17A to 17Cis mounted on the printed-wiring board 210 provided in an electricdevice in the following manner. That is, the terminal pins 206 a and 206b are inserted into or allowed to come into contact with connectingterminals provided on the printed-wiring board 210 incorporated in theelectric device side to solder them and mount the fuel cell on theprinted-wiring board. Thus, the electrodes of the fuel cell 241 areelectrically connected to wiring formed on the printed-wiring board 210so that electric power is supplied to the circuit of the electric deviceside.

Each power generator 203 has a structure that an ion conductive film 203a is held at both sides between an anode 203 b and a cathode 203 c as apair of electrodes and peripheries thereof are sealed with seals 203 d,as shown in FIG. 18. This seal 203 d is provided for the purpose ofpreventing hydrogen from leaking to the cathode side 203 c. The seal 203d may be formed by bonding together materials which are previouslyformed by an injection molding or punching, or the like or may bedirectly formed on the ion conductive film 203 a or the electrodes.

FIG. 19 shows a state that the fuel cell 241 shown in FIGS. 17A to 17Cis disassembled. The fuel cell 241 of this embodiment has a structurethat the power generator 203 shown in FIG. 18 is sandwiched in between apair of current collectors 207 and 208. The current collectors 207 and208 respectively have opening parts 207 a and 208 a providedrespectively for taking fuel. Hydrogen as fuel and oxygen (air) aretaken into the anode 203 b and the cathode 203 c through these openingparts 207 a and 208 a.

The current collector 207 of the cathode 203 c side has a two-layerstructure. The structure includes an insulating material layer 207 bmade of an insulating material in an exposed side as the surface of theupper housing 201 and a current collecting part 207 c made of aconductive material in a side coming into contact with the powergenerator 203. The current collector 208 of the anode 203 b side is madeof a conductive material, and is not especially provided with such aninsulating material layer as that provided in the current collector 207of the cathode 203 c side. Here, as the conductive material which formsthe current collecting part 207 c of the current collector 207 in thecathode 203 c side or the current collector 208 of the anode 203 b side,a metallic plate, a carbon sheet or the like may be used. In additionthereto, what is called a single-sided board that a conductive layer isformed on a polymer film, a glass epoxy board, a ceramic board, and/orthe like may be used. Otherwise, a paste printing or plating may beapplied to the power generator 203 to directly form a current collectinglayer thereon.

The current collecting part 207 c of the current collector 207 or thecurrent collector 208 is electrically connected respectively to theterminal pins 206 a and 206 b through which an electric connection tothe electric device is achieved. The ends of the terminal pins 206 a and206 b are desirably have forms, for instance, thin plate shapes or pinshapes so as to be inserted into or come into contact with theconnecting terminals provided in the printed-wiring board 210. Further,the ends of the terminal pins 206 a and 206 b desirably have such arigidity as to be fixed to the printed-wiring board 210. When thecurrent collecting part 207 c of the current collector 207 or thecurrent collector 208 is made of the metallic plate, the ends of theterminal pins 206 a and 206 b are machined to the thin plate shapes orpin shapes, so that they may be provided integrally. The terminal pins206 a and 206 b may be separately provided and they may be mechanicallyand electrically connected to the current collecting part 207 c of thecurrent collector 207 or the current collector 208.

In the outside of the current collector 208 of the anode side, ahydrogen supply part 209 having a passage 209 a for hydrogen as fuelfluid is arranged and a fuel joint 205 is fixed thereto. Further, in thehydrogen supply part 209, opening parts 209 b opposed to the openingparts 208 a provided in the current collector 208 are provided.Accordingly, the fuel fluid such as hydrogen is supplied to the anode203 b of the power generator 203 through the passage 209 a, the openingparts 209 b and the opening parts 208 a from the fuel joint 205. Thefuel joint 205 may be formed as one part, or may be formed integrallywith the fuel supply part 209, the current collector 208 or the boardside housing 202.

The above-described components, that is, the power generator 203, thefuel joints 205, the current collectors 207 and 208, and the hydrogensupply part 209 are superposed together to have a laminated body. Then,these components are fixed together by sandwiching them in between theupper housing 201 and the board side housing 202 and bonding them tohave a packaged body as shown in FIG. 20. In this embodiment, thehousing is divided into upper and lower parts and the laminated body issandwiched in between these housings and fixed by an adhesive. However,it is to be understood that variety of structures other than thisstructure may be employed. For instance, a packaging of the laminatedbody may be carried out simultaneously with a formation of the housingby a resin mold to form the housing integrally with the laminated body.In addition, a structure that the upper and lower housings are fixed byscrewing or a structure that the upper and lower housing parts are fixedby an ultrasonic welding or the like may be employed.

In the fuel cell having the above-described structures, when thehydrogen as fuel is allowed to enter the hydrogen supply part 209 fromthe fuel joints 205 so as to come into contact with the anode 203 b andair (oxygen) is allowed to enter from the opening parts 207 a so as tocome into contact with the cathode 203 c, a reaction represented by thefollowing reaction formula is generated in the anode 203 b side.H₂2H⁺+2e—

In the cathode 203 c side, a reaction represented by a reaction formuladescribed below is generated.½O₂₊2H⁺+2e—H₂O+heat of reaction Q

In the entire part, a reaction represented by H₂+½O₂ H₂O is generated.That is, in the anode 203 b side, hydrogen discharges an electron tobecome a proton that passes through the ion conductive film 203 a tomove to the cathode 203 c side and receives the supply of the electronin the cathode 203 c to react with oxygen. An electromotive force isobtained in accordance with such an electrochemical reaction.

FIGS. 21A to 21C show plan views showing the structure of theprinted-wiring board 210 shown in FIG. 16. The printed-wiring board 210is what is called a glass epoxy board that glass fibers are impregnatedwith an epoxy resin. The printed-wiring board 210 has a three-layerstructure including an upper layer 210 a, an inner layer 210 b and alower layer 210 c. In the upper layer 210 a, connecting terminals 212for an electric connection to fuel supply ports 211 as opening parts areformed so as to correspond to positions where the above-described fuelcells 240 are mounted. That is, the fuel supply ports 211 are formed atpositions suitably connected to the fuel joints 205 formed in the fuelcells 240. The connecting terminals 212 are formed at positionscorresponding to the terminal pins 206 a and 206 b formed in the fuelcells 240.

Although the example that the printed-wiring board 210 is the glassepoxy board is described, such a wiring member as described below may beemployed. This wiring member has wiring for electrically connectingtogether electronic parts such as a semiconductor device, a fuel cell,or the like and a mechanical strength with which fuel does not leakunder atmospheric pressure. Further, what is called an inorganicsubstrate in which an inorganic material such as glass, ceramics, or thelike is used as a substrate member and wiring is applied thereon or aflexible substrate with a flexibility using polyimide, PET, or the likemay be used. Further, tubular fuel passages may be embedded in a sheetor a plate shaped wiring member to form a printed-wiring board.

On the upper layer 210 a, an electric device 213 on which printed wiringnot shown is applied is mounted, or the terminals for mounting theelectric device 213 are formed. The printed wiring is connected to eachof the connecting terminals 212 to drive the electric device 213 undervoltage generated by the mounted fuel cells 241. The printed wiring, thefuel supply ports 211 and the connecting terminals 212 are manufacturedby the same method as a method for forming an ordinary printed board.

On the inner layer 210 b, fuel passages 214 a and 214 b are formedthrough positions corresponding to the fuel supply ports 211 by amilling, an embossing, a routing, etc. The fuel passages 214 a and 214 bmay pass through both the surfaces of the inner layer 210 b or may beformed in shapes of grooves with one surface left. In this case, asectional area capable of adequately supplying fuel needs to be ensured.At positions corresponding to the fuel supply ports 211, the fuelpassages 214 a and 214 b are desirably formed in a range wider than thediameter of the fuel supply port 211 by considering a dislocation uponlaminating process. When the fuel is supplied, the fuel supply tube 250shown in FIG. 16 is connected to the fuel passages 214 a and 214 b sothat the fuel enters the fuel passages 214 a and 214 b from the fuelsupply tube 250.

The lower layer 210 c is made of a plate shaped synthetic resin andcovers the fuel passages 214 a and 214 b formed on the inner layer 210 bfrom a surface opposite to the upper layer 210 a to prevent the leakageof fuel from the fuel passages 214 a and 214 b.

FIG. 22 is a perspective view showing a positional relation when theabove-described upper layer 210 a, the inner layer 210 b and the lowerlayer 210 c are combined and bonded together to form the printed-wiringboard 210. The upper layer 210 a, the inner layer 210 b and the lowerlayer 210 c are bonded together by an adhesive. At this time, the fuelsupport ports 211 formed on the upper layer 210 a are located so as tobe opposed to the fuel passages 214 a and 214 b formed on the innerlayer 210 b. Here, although the three-layer structure is described, theinner layer 210 b may be formed while the inner layer 210 b is formedintegrally with the lower layer 210 c. Further, when the printed-wiringboard having a multi-layer wiring structure is formed, layers may beincreased and wiring may be properly provided respectively between thelayers.

FIGS. 23A to 23C are sectional views showing steps for mounting the fuelcell 241 shown in FIG. 20 on the printed-wiring board 210. A conductiveagent 215 is printed on the connecting terminals 212 of theprinted-wiring board 210 in which the upper layer 210 a, the inner layer210 b and the lower layer 210 c are bonded together and formedintegrally by an adhesive or the like. As the conductive agent 215,cream solder or conductive paste may be exemplified. Any material may beemployed which has a curing property after printed at a prescribedposition as well as an electric conductivity for ensuring an electricconnection between the terminal pins 206 a and 206 b and the connectingterminals 212. At this time, the ion conductive film 203 a of the fuelcell 241 is made of a material having a low heat resistance, a coldsetting type conductive agent 215 is used. Further, in an area on whichthe fuel cell 241 is mounted in the vicinity of the fuel supply ports211 formed on the surface of the upper layer 210 a, an adhesive 216 islaminated (see FIG. 23A). Here, as the adhesive 216, a thermoplasticadhesive sheet made of polyester resin or the like may be exemplified.Any material by which the printed-wiring board 210 can be bonded to thefuel cell 241 may be employed. Further, a material that can maintain anair-tightness under atmospheric pressure or the like after it is curedis desirably used.

The terminal pins 206 a and 206 b of the fuel cell 241 are positioned onthe positions of the connecting terminals 212 and the fuel joints 205are positioned on the positions of the fuel supply ports 211 and thefuel passages 214 a and 214 b. Thus, the fuel joints 205 are insertedinto the fuel supply ports 211 to mount the fuel cell 241 on theprinted-wiring board 210. At this time, pressure is suitably applied(see FIG. 23B). Thus, the terminal pins 206 a and 206 b of the fuel cell241 adequately come into contact with the conductive agent 215 and thewiring member mounting surface of the board side housing 202 adequatelycomes into contact with the adhesive 216.

After the fuel cell 241 is mounted on the printed-wiring board 210, areflowing process is carried out to cure the conductive agent 215,solder them and electrically connect the wiring provided on theprinted-wiring board 210 to the fuel cell 241. At this time, theadhesive 216 is also cured simultaneously to stick the fuel cell 241 tothe printed-wiring board 210. When temperature conditions under whichthe conductive agent 215 and the adhesive 216 are cured are differentfrom each other, they are respectively cured at two-stage settingtemperature. The adhesive 216 is sandwiched in between the board sidehousing 202 and the printed-wiring board 210 so that the fuel can besealed between the fuel joints 205, the fuel supply ports 211 and thefuel cell 241 to prevent the leakage of the fuel (see FIG. 23C).

FIGS. 24A to 24C show another embodiment of steps for mounting a fuelcell 241 on a printed-wiring board 210. An upper layer 210 a, an innerlayer 210 b and a lower layer 210 c are bonded together and formedintegrally by an adhesive or the like. A conductive agent 215 is printedon the connecting terminals 212 of the integrally formed printed-wiringboard 210. At this time, the ion conductive film 203 a of the fuel cell241 is made of a material having a low heat resistance, a cold settingtype conductive agent 215 is used. Further, in a part of an area of thesurface of the upper layer 210 a on which the fuel cell 241 is mounted,a thermoplastic adhesive 216 is laminated (see FIG. 24A).

The terminal pins 206 a and 206 b of the fuel cell 241 are positioned onthe positions of the connecting terminals 212 and fuel joints 205 arepositioned on the positions of fuel supply ports 211 and fuel passages214 a and 214 b. Thus, the fuel cell 241 is mounted on theprinted-wiring board 210 so that the fuel joints 205 are connected tothe fuel supply ports 211. In the peripheries of the fuel joints 205,airtight members 217 for holding air-tightness such as O-rings or fuelsockets are arranged to hold the airtight members 217 between theprinted-wiring board 210 and the fuel cell 241. At this time, pressureis suitably applied (see FIG. 24B). Thus, the terminal pins 206 a and206 b adequately come into contact with the conductive agent 215 and thewiring member mounting surface of a board side housing 202 adequatelycomes into contact with the adhesive 216. Accordingly, the airtightmember 217 allows the air-tightness between the surface of theprinted-wiring board 210 and the wiring member mounting surface of thefuel cell 241 to be maintained.

After the fuel cell 241 is mounted on the printed-wiring board 210, areflowing process is carried out to cure the conductive agent 215,solder them and electrically connect the wiring provided on theprinted-wiring board 210 to the fuel cell 241. At this time, theadhesive 216 is also cured simultaneously to stick the fuel cell 241 tothe printed-wiring board 210. When temperature conditions under whichthe conductive agent 215 and the adhesive 216 are cured are differentfrom each other, the conductive agent and the adhesive are respectivelycured at two-stage setting temperature. The airtight members 217 aresandwiched in between the board side housing 202 and the printed-wiringboard 210. Thus, the fuel can be sealed between the surface of theprinted-wiring board 210 and the wiring member mounting surface of thefuel cell 241 to prevent the leakage of the fuel (see FIG. 24C).

In order to more improve the air-tightness between the printed-wiringboard 210 and the fuel cell 241, a sealing resin 218 such as a epoxyresin is injected into clearances between the printed-wiring board 210and the fuel cell 241 and heat-treated. Thus, the sealing resin 218 iscured to realize resin sealing. The fuel cell 241 is securely fixed tothe printed-wiring board 210 by the resin sealing to seal the fuelbetween the fuel joints 205, the fuel supply ports 211 and the fuel cell241 and prevent the leakage of the fuel. As the sealing resin 218, athermoplastic resin is used so that the fuel cell may be reworked andeasily repaired and parts may be easily changed.

As described above, the fuel supply tube 250 shown in FIG. 16 isconnected to the fuel passages 214 a and 214 b provided on theprinted-wiring board 210 and the fuel such as hydrogen is injected tothe printed-wiring board 210 from the fuel supply tube 250. Then, thefuel enters the fuel passages 214 a and 214 b of the inner layer 210 band reaches the fuel supply ports 211 provided in the upper layer 210 a.The fuel reaching the fuel supply ports 211 enters the fuel supply part209 through the fuel joints 205 to supply the fuel to the powergenerator 203.

As described above, in the power generator 203, hydrogen discharges theelectron in the anode 203 b side to become a proton. The proton passesthrough the ion conductive film 203 a and moves to the cathode 203 cside and receives the supply of an electron to react with oxygen andproduce water in the cathode 203 c side. In such a way, the fuel can becontinuously supplied to the fuel cell 241 mounted on the surfacethrough the fuel passages provided on the printed-wiring board 210.Here, the example that the fuel is supplied to the fuel joints 205 fromthe two systems of the fuel passages 214 a and 214 b is illustratedabove. However, such a design as to supply fuel from one system or moresystems is made depending on the size or the form of the fuel cell 241,a flow rate allowable by the fuel passages 214, etc.

Now, a still another embodiment of a fuel cell according to the presentinvention will be described. A fuel cell 242 according to thisembodiment utilizes a surface-mount type package form called a BGA (BallGrid Array).

The basic structure of the fuel cell 242 of this embodiment is the sameas that of the above-described embodiment. As shown in FIGS. 26A to 26C,a power generator 223 is contained in a housing 221. Air is supplied toa cathode side from air intake ports 224 provided in the housing 221 andfuel (hydrogen) is supplied to an anode side from tubular fuel joints225 likewise attached to the housing 221 to generate electric power.

An electric connection to an electric device is carried out throughterminals 226. Here, the terminals 226 are formed in the shapes of ballssuch as what is called solder bumps or protrusions made of a conductivematerial such as solder differently from those of the above-describedembodiment. The terminals 226 are mechanically and electricallyconnected to connecting terminals 212 formed on a printed-wiring board210 of the electric device side.

FIG. 27 is a schematic sectional view showing a state that the fuel cell242 shown in FIGS. 26A to 26C is disassembled. The structure of thecontained power generator 223 is the same as that of the above-describedembodiment. The power generator 223 has a structure that an ionconductive film 223 a is held at both sides between a pair ofelectrodes, that is, an anode 223 b and a cathode 223 c and peripheriesthereof are sealed with a seal 223 d. The power generator 223 issandwiched in between a base substrate 227 and a fuel supply part 228.The base substrate 227 forms a part of the housing 221 and employs, forinstance, a resin substrate such as glass epoxy, phenolic resin,polyimide, etc., or an inorganic substrate such as ceramics, glass,silicon, etc. The base substrate 227 has a recessed part 227 a capableof housing the power generator 223. Air intake opening parts 227 b areformed correspondingly to the recessed part 227 a. Cathode currentcollectors 229 are formed on the inner surface of the base substrate227, that is, a surface that comes into contact with the cathode 223 cof the power generator 223.

On the other hand, the fuel supply part 228 is arranged so as to coverthe power generator 223 housed in the base substrate 227. The fuelsupply part 228 has a passage 228 a for hydrogen as fuel fluid andhydrogen intake opening parts 228 b formed on a surface that comes intocontact with the anode 223 b of the power generator 223. Further, thehydrogen intake opening parts 228 b are formed on a wiring membermounting surface of the power generator 223. On the surface of the fuelsupply part 228 that comes into contact with the anode 223 b of thepower generating 223, anode current collectors 230 are formedintegrally. Otherwise, the fuel supply part 228 itself may be made of aconductive material to serve as an anode current collector.

The power generator 223 is sandwiched in between the base substrate 227and the fuel supply part 228 so that the current collecting structuresof the anode 223 b and the cathode 223 c of the power generator 223 arerealized. In this embodiment, the base substrate 227 has a three-layerstructure. In the parts of the base substrate 227 that come into contactwith the fuel supply part 228, wiring layers 231 connected to the anodecurrent collectors 230 are formed. Electric connections between therespective layers are carried out through via holes 232 and 233. Thefuel supply part 228 is preferably fixed to the base substrate 227 underthis state. Further, the fuel supply part 228 may be fixed to the basesubstrate 227 simultaneously with the attachment of a cover substrate asdescribed below. As a fixing method, a bonding method by a resin may beexemplified.

In the back surface side of the base substrate 227 located in the lowerpart of FIG. 27, a cover substrate 234 is provided. The power generator223 and the fuel supply part 228 are secured in the recessed part 227 aby the cover substrate 234. In the cover substrate 234, via holes 235and 236 are provided so as to correspond to the via holes 232 and 233.Further, hemispherical terminals 226 are formed so as to correspond tothe via holes 235 and 236. As the hemispherical terminals 226, forinstance, solder balls can be used. The solder balls are fixed to theconnecting terminals 212 formed on the printed-wiring board 210 of theelectric device side by performing a reflowing process to achieve anelectric connection. Further, on the cover substrate 234, the fueljoints 225 as the tubular fuel passages are formed at positionscorresponding to the opening parts 228 b formed on the wiring membermounting surface side of the fuel supply part 228.

FIG. 28 shows an assembled state of the fuel cell. Under the assembledstate, the housing 221 is formed and packaged by the base substrate 227and the cover substrate 234. The fuel joints 225 and the terminals 226are arranged on the wiring member mounting surface. Accordingly, thefuel cell 242 having the above-described structure is configured as afuel cell having a surface-mount type package. The surface-mount typepackage form is not limited to the BGA and, for instance, a QFP (QuadFlat Package) or the like may be used.

FIGS. 29A to 29D show sectional views showing steps for mounting thefuel cell 242 shown in FIG. 26 on a printed-wiring board 210. Connectingterminals 212 are formed on the printed-wiring board 210 in which anupper layer 210 a, an inner layer 210 b and a lower layer 210 c arebonded together by an adhesive or the like and integrally formed (seeFIG. 29A). The terminals 226 of the fuel cell 242 are positioned on thepositions of the connecting terminals 212 and the fuel joints 225 arepositioned on the positions of fuel supports ports 211 and fuel passages214 a and 214 b. Thus, the fuel joints 225 are connected to the fuelsupport ports 211 to mount the fuel cell 242 on the printed-wiring board210 (see FIG. 29B)

After the fuel cell 242 is mounted on the printed-wiring board 210, areflowing process is carried out to solder the terminals 226 to theconnecting terminals 212 and electrically connect wiring provided on theprinted-wiring board 210 to the fuel cell 242 (see FIG. 29C). Afterthat, a sealing resin 237 is injected into clearances between theprinted-wiring board 210 and the fuel cell 242 and heat-treated to curethe sealing resin 237 and perform resin sealing. The fuel cell 242 issecurely fixed to the printed-wiring board 210 by the resin sealing toseal the fuel between the fuel joints 225, the fuel supply ports 211 andthe fuel cell 242 and prevent the leakage of the fuel (see FIG. 29D). Asthe sealing resin 237, an epoxy resin or the like may be employed.

Also in the above-described embodiment, the fuel supply tube 250 isconnected to the fuel passages 214 a and 214 b provided on theprinted-wiring board 210 and the fuel such as hydrogen is injected tothe printed-wiring board 210 from the fuel supply tube 250. Then, thefuel enters the fuel passages 214 a and 214 b of the inner layer 210 band reaches the fuel supply ports 211 provided in the upper layer 210 a.The fuel reaching the fuel supply ports 211 enters the fuel supply part228 through the fuel joints 225 to supply the fuel to the powergenerator 223.

As described above, in the power generator 223, hydrogen discharges anelectron in the anode 223 b side to become a proton. The proton passesthrough the ion conductive film 223 a and moves to the cathode 223 cside and receives the supply of the electron to react with oxygen andproduce water in the cathode 223 c. In such a way, the fuel can becontinuously supplied to the fuel cell 242 mounted on the surfacethrough the fuel passages provided on the printed-wiring board 210.Here, the example that the fuel is supplied to the fuel joints 225 fromthe two systems of the fuel passages 214 a and 214 b is illustratedabove. However, such a design as to supply fuel from one system or moresystems may be realized depending on the size or the form of the fuelcell 242, a flow rate allowable by the fuel passages 214, etc.

FIG. 30 is a schematic view of an electric device showing that aprinted-wiring board 210 is connected to fuel cells 243 by theabove-described connecting method. On the printed-wiring board 210, aplurality of fuel cells 243 are mounted and a fuel supply tube 250 isconnected to fuel passages 214 a and 214 b (illustrations are omitted)formed on the printed-wiring board 210. Further, on the upper layer ofthe printed-wiring board 210, electronic parts 238 such as semiconductordevices are mounted. Further, connecting terminals 212 and electricwiring 239 formed on the printed-wiring board 210 allow the fuel cells243 to be electrically connected to the electronic parts 238. Theelectronic parts 238 and the fuel cells 243 may be mounted on theprinted-wiring board 210 by respectively separate steps. When the fuelcells 243 are mounted, a reflowing process or resin sealing may besimultaneously carried out.

Fuel is supplied to the fuel cells 243 from the fuel supply tube 250through the fuel passages 214 of the printed-wiring board 210 and air istaken from air intake ports 204 c to drive the electronic parts 238 byelectric power generated by the fuel cells 243.

The fuel of the fuel cell according to the present invention is notlimited to hydrogen gas, and other fuels such as liquefied hydrogen,methane, ethane, propane, isobutane, n-butane, hexane, heptane, octane,nonane, decane, methanol, or the like may be used.

INDUSTRIAL APPLICABILITY

As mentioned above, the fuel cell according to an embodiment of thepresent invention can be directly mounted on a mounting board and a fuelcell housing part does not need to be provided on the electric device onwhich the fuel cell is mounted. Accordingly, the wiring or the connectorfrom the device, the space for housing, the fixing means, the cover, orthe like are not necessary so that the structure of the device can besimplified and miniaturized. The fuel cell or the power generator isdirectly mounted on the mounting board so that a restriction in designsuch as the arrangement of the device or wiring patterns, etc. can bereduced. Free layouts can be realized, for instance, the fuel cell canbe disposed near the device having large consumed power or plural fuelcells can be arranged. Therefore, unnecessary wiring or space and theloss of output, etc. can be decreased.

Further, when the fuel cell according to an embodiment of the presentinvention is manufactured, the production technology and a device of,what is called a semiconductor post-process, for instance, a multi-layerboard is used for a housing or a packaging by a resin mold can beutilized to easily realize a mass production. Since the fuel cell ispackaged so that the fuel cell can be incorporated in the electricdevice in a production site by an ordinarily used component mountingapparatus, the production steps of the device can be reduced.Furthermore, since the dimension of the package, the form and dimensionof a terminal, mounting steps, etc. are easily standardized, acompatibility can be improved.

Since the fuel cell according to an embodiment of the present inventionis fixed and electrically connected to the electric device and thepiping of fuel are all carried out by one process, assembly steps can begreatly reduced. Further, since the mounting of the fuel cell on thedevice and the piping of fuel can be achieved by using a conventionalchip mounting apparatus, new plant and equipment investment is notrequired. Still further, since the fuel cell is fixed and electricallyconnected to the electric device and the piping for fuel is provided onthe lower surface of the fuel cell, connecting parts or an attachingspace are not necessary so that the device can be miniaturized.

Since the fuel cell according to an embodiment of the present inventioncan be directly connected to the passages formed on the printed-wiringboard, a fuel sealing with a higher air-tightness can be realized.Further, when a thermoplastic resin is used as a sealing resin, the fuelcell can be reworked and easily repaired and parts thereof can bereadily replaced by other parts.

The electronic parts and the fuel cell are mounted in a mixed way on theprinted-wiring board so that the electric device can be miniaturized anda production process can be shortened.

According to the printed-wiring board and a method for manufacturing itaccording to the present invention, a new printed-wiring board havingnot only a function as a circuit board, but also a function as fuelpassages can be provided. Further, according to the electric deviceaccording to the present invention, a restriction in design can belightened, the number of parts can be decreased and the device can beminiaturized. Still further, according to the connector for a fuel cellaccording to an embodiment of the present invention, an electricconnection can also serve as fuel joints between a power generating celland a fuel supply source, and a new connection form can be provided.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present invention andwithout diminishing its intended advantages. It is therefore intendedthat such changes and modifications be covered by the appended claims.

The invention claimed is:
 1. An electronic board comprising: a fuelpassage layer that comprises an insulating material and that defines atleast one inner fuel passage space, the fuel passage layer including aplurality of openings formed into a surface of the fuel passage layer,the openings enabling a fuel to be communicated from the inner fuelpassage to a power generator of a fuel cell, wherein the openings areformed at positions corresponding to fuel ports, and wiring patternsformed on both sides of the fuel passage layer such that positions ofthe wiring patterns are different than the positions of the openings; afirst wiring layer including an insulating base and wiring patternsformed on both surfaces of the insulating base, the first wiring layerformed on the surface of the fuel passage layer and including aplurality of openings, each one of the openings of the first wiringlayer fluidly connected to a respective one of the openings formed intothe surface of the fuel passage layer; and a second wiring layerincluding an insulting base and wiring patterns formed on both surfacesof the insulating base, the second wiring layer formed on a secondsurface of the fuel passage layer such that the fuel passage layer is aninner layer, wherein wirings formed on both sides of the first wiringlayer, the fuel passage layer and the second wiring layer areelectrically interconnect through contact holes formed in the firstwiring layer, the fuel passage layer and the second wiring layer.
 2. Theelectronic board according to claim 1, wherein the at least one innerfuel passage space is shaped as at least one of a groove and a bore. 3.The electronic board according to claim 1, wherein the at least oneinner fuel passage space includes at least one pipe-shaped part.
 4. Theelectronic board according to claim 1, wherein the fuel ports arelocated so as to be opposed to the openings formed in the fuel passagelayer.
 5. The electronic board according to claim 1, wherein theelectronic board is incorporated in an electric device.
 6. Theelectronic board according to claim 5, wherein the electronic board is acircuit board of the electric device.
 7. The electronic board accordingto claim 1, wherein the first wiring layer, the fuel passage layer andthe second wiring layer are laminated and pressed together to form anintegrated electronic board.
 8. The electronic board according to claim1, wherein the second wiring layer covers the inner fuel passage toprevent fuel leakage.